1. Field of the Invention
The present invention generally relates to a robot apparatus which can behave autonomously to have realistic communications with the user and a method of controlling the behavior of the robot apparatus, and more particularly to an autonomous robot apparatus which can recognize surroundings thereof including images and sounds and behave itself in response to such conditions, and a behavior control method for the robot apparatus.
This application claims the priority of the Japanese Patent Application No. 2002-257097 filed on Sep. 2, 2002, the entirety of which is incorporated by reference herein.
2. Description of the Related Art
A machine or device capable of performing like a human being (animal) by electrical or magnetic operations is called “robot”. In Japan, the robots had started prevailing in the late 1960s. Many of the robots were industrial robots such as manipulators, transport robots and the like intended for automation, unmanning, etc. of the factory production lines.
Recently, there have been developed utility robots which support the human life as a partner of the human being, that is, support the human activities in the residential environment and other daily living situations. Different from the industrial robots, the utility robots have abilities of autonomically learning how to adapt themselves to human beings different in personality from each other in various aspects of the human beings' living environments or to various environments or to various environments. There are being put to practical use the “pet” robots simulating the physical mechanism and behaviors (motions or actions) of a quadrupedal walking animal such as a dog or cat and the “humanoid” robots designed based on the physical mechanism and behaviors of the human being or the like walking on two feet, for example.
Since the above “pet” and “humanoid” robots can perform various behaviors designed with major consideration to the entertainment as compared with the industrial robots, they are often called “entertainment robots”. Some of the entertainment robots autonomously behave adaptively to external information and internal status.
Generally, the robot of such an autonomous type selects a sequence of behaviors correspondingly to change in environments including images and sounds. Also, some of the autonomous robots have other behavior selection mechanisms which models emotions such as instinct and feeling for managing the internal status of the system and selecting a behavior correspondingly to a change of the internal status. It should be noted that the system internal status is changed as the environment changes and also when the robot does the selected behavior.
Since a robot has to be designed with considerations given to resources such as a hardware and software and required behavior of the robot, many of behavior modules are implemented on demand.
Actually, a behavior as a whole can be implemented monolithically, that is, by one software module. To implement a more complicated behavior, however, a behavior may be modularized, namely, it may be decomposed into a plurality of modules to implement the behavior by interactions among the modules.
However, when any one of the modules is used to implement another behavior, the procedure of interaction between the modules and the modules themselves have to radically be rewritten for that purpose in some cases. The modules are difficult to recombine.